The present invention relates to improvements in and relating to sorting apparatus and methods for use in sorting. The present invention relates to the sorting of any type of product but for simplicity will be described particularly in respect of the sorting of fruit or other food product.
The term “sorting” is used throughout this specification to include any identification process including merely counting.
In the sorting of fruit a large number of randomly sized fruit of a particular type typically need to be sorted and this sorting can be for a variety of purposes including to sort the fruit into groups having similar properties and/or the required combined weight.
To the present time the applicant is aware of two basic types of sorting equipment.
The first type relies on a conveyor to deliver fruit or other products to a number of fixed delivery points along the length of the machine with each delivery point accepting fruit having certain characteristics such as weight or size. With this type of machine the number and location of each delivery point or “drop” is fixed by the physical design of the equipment. For example a fruit grading machine may have 10 outlets along its length into which it can deliver fruit. Therefore this machine could only grade fruit into 10 different categories at any one point in time although categories may be mixed at the respective outlets.
The second type of sorting machine provides for the random delivery of products to a number of outlets. The weight of the products at the respective outlets will then be weighed and from the measurements taken, the best combination of individual outlets are chosen to give the required weight. For example the sorting machine may have 12 collection outlets each of which may be filled with fruit and individually weighed. If then the fruit in each outlet weighed about 100 grams and a bag was required to be filled with one kilogram of fruit, then the 10 outlets which most closely added to this target weight would be selected and emptied into a common chute to fill the bag. Although this method can be used to deliver a constantly variable output i.e. the output weight of every cycle can be different, it is limited by the fact that the fruit is randomly allocated to the outlets. This random allocation means that the consistency in size or colour of the fruit being delivered by the grader would only be as consistent as the fruit being fed into it. These machines therefore often require a pre-grader.
It will be seen therefore that existing grading systems are either limited in their number of outlets (and hence variety of grades of product) or require the use of a pre-grader of some form.
The reference to the above existing systems does not indicate that they form part of common general knowledge in any specific country or region in the world.